Safety belt roll-up device, especially for protecting persons in motor vehicles

ABSTRACT

Safety belt roll-up device having a housing and a one-piece belt carrier. The housing has a base plate with two side walls extending from the base plate. At least one of the two side walls can be set at an angle and bent into a position in which both side walls are parallel. Each side wall has an opening through which a free end of the one-piece belt carrier extends. The one-piece belt carrier is in the form of a single piece including a belt shaft and a belt reel with a reel flange at each end of the belt reel. The belt reel has a diameter greater than the diameter of the opening in the side wall. The belt carrier is inserted between the side walls bent apart in V-shape. The belt carrier is held at the height of the openings and the end walls moved together to a parallel position.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a safety belt roll-up device having a U-shapedhousing, i.e. a base plate with two parallel end walls extendingtherefrom, and a belt shaft with its free ends extending through holesin the two end walls and to a method for manufacturing such a safetybelt roll-up device.

2. Description of the Prior Art

A U-shaped roll-up device housing made of sheet steel is used in knownsafety belt roll-up devices of this type. The side walls of the housingsupport the belt shaft and the belt reel. For this purpose, relativelylarge openings are provided in the side walls through which the freeends of the belt shaft extend and are supported freely rotatably inresilient bearings, for instance, laterally to the side walls. Supportedon the belt shaft, secured against rotation, between the side walls is aspecial belt reel consisting, for instance, of plastic material withlateral reel flanges, the diameter of which is larger than that of theabove-mentioned openings or holes in the side walls. Locking discs whichare, for instance, serrated on both sides may be provided and likewiseconnected, secured against rotation, to the stable belt reel. Thelocking discs are located inside the holes and cooperate with a ratchetwhich releases automatically in case of danger such that the belt shaftand therefore, the belt reel is blocked immediately after the release. Aflexible safety belt is wound on the belt reel. In assembling the safetybelt roll-up device, the belt reel is first inserted between themutually parallel side walls at the housing, whereupon the belt shaft ismoved into its desired position axially through the holes and through acentral hole in the belt reel. After the belt reel and the belt shaftare connected to each other secure against rotation, the belt reel ofthe belt shaft serves for axial security, i.e. prevents axial movement.As is customary, the belt shaft is connected with a rewinding spring onone side of the housing, while the release mechanism for the ratchetpawl is arranged on the other housing side. From the above it will beevident that the unit which carries and supports the safety beltrequires two separately produced parts. Further the assembly of theseparts, due to the necessity alone of feeding these parts, i.e. the beltshaft and the belt reel in different directions, is relativelycomplicated and expensive, and this does not include the parts or meanswhich are required to connect the belt shaft and the belt reel to eachother and make them secure against rotation relative to each other.

SUMMARY OF THE INVENTION

An object of the invention is to provide a safety belt roll-up device ofthe type mentioned in which the assembly effort is reduced and themanufacturing costs overall are decreased. Also, the part of the roll-updevice serving to support the safety belt is of simpler design withgreater strength.

With the foregoing and other objects in view, there is provided inaccordance with the invention a safety belt roll-up device adaptedparticularly for use in motor vehicles comprising a housing and aone-piece belt carrier, said housing having a base plate with two sidewalls extending from the base plate and having at least one of said twoside walls which can be set at a diverging angle and bent into aposition in which both side walls are parallel, an opening in each sidewall through which a free end of the one-piece belt carrier extends,said one-piece belt carrier incorporating in a single piece a belt shaftand a belt reel with a reel flange at each end of the belt reel, saidreel flange having a diameter greater than the diameter of said openingin the side wall.

In accordance with the invention, there is provided a method for themanufacture of a safety belt roll-up device comprising a housing and aone-piece belt carrier, said housing having a base plate with two sidewalls extending from the base plate, and an opening in each side wallthrough which a free end of the one-piece belt carrier extends, saidone-piece belt carrier incorporating in a single piece a belt shaft anda belt reel with a reel flange at each end of the belt reel, said beltreel flange having a diameter greater than the diameter of said openingin the side wall, which comprises inserting the belt carrier between theside walls of the housing which are bent apart in V-shape to permitready insertion of the belt carrier between the side walls, maintainingthe belt carrier at the height of the openings, and moving the sidewalls together in a position parallel to each other causing the freeends of the belt carrier to extend through the openings in the sidewalls and the belt carrier to be retained within the side walls.

Other features which are considered as characteristic for the inventionare set forth in the appended claims.

Although the invention is illustrated and described herein as embodiedin a safety belt roll-up device, especially for protecting persons inmotor vehicles, it is nevertheless not intended to be limited to thedetails shown, since various modifications may be made therein withoutdeparting from the spirit of the invention and within the scope andrange of equivalents of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention, however, together with additional objects and advantagesthereof will be best understood from the following description when readin connection with the accompanying drawings, in which:

FIG. 1 shows a cross-sectional view of a conventional safety beltroll-up device,

FIGS. 2 and 3 show cross-sectional views of the safety belt roll-updevice according to the invention in two different phases of assembly.In FIG. 2 the side walls of the housing have a V-shape to permit readyinsertion of the one-piece belt carrier between the two walls. In FIG. 3the two end walls are shown moved to a position in which they areparallel to each other,

FIG. 4 shows a perspective view of the safety belt roll-up deviceaccording to the invention, and

FIG. 5 is an exploded view of the safety belt roll-up device accordingto the preceding figures.

DETAILED DESCRIPTION OF THE INVENTION

According to the invention, the belt reel and belt shaft and, ifapplicable, also the blocking teeth with journal bearings consist of asingle strong part in which connecting means for connecting theabove-mentioned parts are not required. The assembly of this one-piecebelt carrier becomes very simple, in that this belt support is insertedbetween the side walls which initially are spaced apart in V-fashion andthen, these side walls are bent into the desired parallel position.These side walls may be additionally locked in the desired position by aspacer part which connects the two side walls to each other at the freeends and prevents them from diverging.

According to one advantageous embodiment of the invention, the axiallength of the belt carrier corresponds substantially to the spacing ofthe outer boundary surfaces of the side walls. The end walls of the beltcarrier can be immediately adjacent to ratchet teeth which then arelocated within the holes in the side walls and cooperate functionally,for instance, with a dual ratchet pawl. By designing the safety beltroll-up device in accordance with the invention, journal bearings may beformed directly at the belt carrier on both sides; the journals thenextend beyond the side walls in the desired position. The assembly ofthe belt carrier provided with ratchet teeth is facilitated by the factthat in a safety belt roll-up device of the described design, thediameter of the holes in the side walls is larger than the outsidediameter of the ratchet teeth, for instance, on both sides of the beltcarrier. Although the axial length of the belt carrier is larger thanthe inside width between the side walls of the roll-up device housing,the belt carrier can be inserted radially between the side walls andinto the holes without difficulty.

In a further embodiment of the invention, the housing has recesses inthe region of the corners between at least one of the side walls and thebase plate of the housing. This facilitates bending of the sides wallsto make them parallel to each other.

According to a method for manufacturing the safety belt roll-up deviceof the type described above, the belt carrier is inserted between theside walls of the belt carrier which are bent apart in V-fashion. Thebelt carrier is held at the height of the holes and held at that leveluntil the side walls are set parallel to each other. A very simpleprocedure for setting the side walls parallel to each other is bystraightening the concave base plate which connects the side walls toeach other. As a result of straightening the concave base plate, theside walls which are initially bent outward in V-shape aresimultaneously brought into the parallel position.

The invention will be explained in the following by means of anembodiment example shown in the drawings.

Only those parts of the known safety belt roll-up device and the safetybelt roll-up device according to the invention are shown in the drawingswhich are essential for understanding the invention.

In the safety belt roll-up device according to FIG. 1, a U-shapedhousing 1 having a base plate 2 and two mutually parallel side walls 3and 4 which extend from the base plate 2 at right angles, is thesupporting part of the roll-up device. The side walls 3 and 4 areprovided with relatively large holes 5 and 6. A metallic belt shaft 7has an axial length between the end corners 8 which corresponds to thespacing of the two outer boundary surfaces of the side walls 3 and 4.Bearing journals 9 follow the end corners 8. Ratchet teeth 10 are at theend corners 8. The outside diameter of the ratchet teeth 10 correspondsubstantially to the shaft diameter of the belt shaft 7. The belt shaft7 is the carrier of a belt reel 11. The latter is a separate part and isconnected, for instance, by connecting means 12 to the belt shaft 7 withthe belt reel 11 secured against rotation relative to the shaft 7. Reelflanges 13, the diameter of which is larger than that of the holes 5 areon both sides of belt reel 11. A flexible safety belt 14 is wound on thebelt reel 11. In the assembly of the safety belt roll-up deviceexplained, the belt reel 11 is first inserted between the side walls 3and 4 of the housing 1 up to the height of the holes 5 in the axialdirection, whereupon the belt shaft 7, shown in FIG. 1 by dashed-dottedlines, is inserted axially in the direction of the arrow into the holes5, and thereby into the central hole in the belt reel 11.

This complicated assembly is substantially facilitated in the safetybelt roll-up device according to FIGS. 2 to 5, by designing the beltshaft 7 and the belt reel 11 of FIG. 1 as a one-piece belt carrier 15.This one-piece belt carrier 15 incorporates on both sides in a singlepiece a roll-up cylinder 16, reel flanges 17 and, adjacent theretospacer extensions 18, ratchet teeth 19 as well as, with a tapereddiameter, bearing journals 20. The diameter of the reel flanges 17 issubstantially larger than the diameter of the holes 5 and 6 in the sidewalls 3 and 4, while the outside diameter of the ratchet teeth 19 issmaller than the interior of the holes 5 and 6. In the center of thebelt carrier 15, is a slot 21 for locking the end of the belt. As shownin FIGS. 4 and 5, recesses 22 and 23 are provided in the region of thecorners between the side walls 3 and 4 and the base plate 2 therebyweakening the bending cross section between the side walls and baseplate. As shown particularly in FIG. 2, the side walls 3 and 4 areinitially set apart in V-shape for the assembly, to permit the beltcarrier 15 to be brought into the desired position. After positioning ofthe one-piece belt carrier 15, the set-apart side walls 3 and 4 arebrought into the parallel position as shown in FIG. 3 by plasticdeformation of the corner regions. This can be accomplished by pushingthe originally convex base plate 2, indicated by the dashed-dotted linesin FIG. 2, in the direction of the arrow to straighten it (FIG. 3). As aresult, the sidewalls 3 and 4 are moved automatically into the parallelposition shown in FIG. 3. In this position, the ratchet teeth 19 arecontained with play within the holes 5 and 6, with the bearing journals20 extending beyond the outside surfaces of the sides 3 and 4. The beltcarrier 15 is supported by means of bearing journals 20, freely androtatably in bearing plates 24 and 25 which are attached to side walls 3and 4. The two side walls 3 and 4 are connected to each other by aspacer 26, as can be seen from FIGS. 4 and 5. Spacer 26 is provided withslots 28 for insertion into slots 27 at the free ends of the side walls3 and 4, and spacer 26 is locked by knurling or peening of the exposededges of the slots 27. It may further be seen from FIGS. 4 and 5 that,in the side walls 3 and 4, adjacent to the holes 5 and 6, are bearingslots 29 in which a double ratchet pawl 30 with pawl extensions 31 ispivoted. This ratchet pawl 30 with its pawl extensions 31 can be movedby a release device, not shown, in the direction of the ratchet teeth 19and comes into engagement with these ratchet teeth. The pawl extensions31 of the pawl 30, as well as the ratchet teeth 19, are located withinthe side walls 3 and 4 of the housing 1.

I claim:
 1. A safety belt roll-up device for use in a motor vehicle,said device comprising a one-piece U-shaped frame formed of sheet metaland having a pair of upstanding leg sections interconnected by aconnector section, each of said leg sections including an outer sidesurface and an inner side surface which extends parallel to said outersurface and faces toward the inner side surface on the other legsection, each of said leg sections including surface means defining anopening extending between the inner and outer side surfaces and having acircular portion with a first diameter, a one-piece belt carrier, saidone-piece belt carrier including a roll-up cylinder around which asafety belt is wound, a pair of circular reel flanges located atopposite axial ends of said roll-up cylinder and having diameters whichare greater than the diameter of said roll-up cylinder and said firstdiameter, a pair of circular positioning shoulders projecting axiallyoutwardly from said reel flanges and having diameters which are greaterthan said first diameter and less than the diameter of said reelflanges, a pair of circular arrays of ratchet teeth projecting axiallyoutwardly from said positioning shoulders and having a diameter which isless than said first diameter, and a pair of cylindrical bearingsections projecting axially outwardly from said circular arrays ofratchet teeth and having diameters which are less than the diameters ofsaid circular arrays of ratchet teeth, said positioning shoulders beingdisposed in abutting engagement with said inner side surfaces of saidleg sections of said frame, said circular arrays of ratchet teeth beingdisposed in said openings in said leg sections of said frame with atleast a major portion of the axial extent of each of said circulararrays of ratchet teeth being disposed between the inner and outer sidesurfaces of said leg sections, a pair of support means disposed adjacentto the outer side surfaces of said leg sections of said frame forengaging said bearing sections and supporting said one-piece beltcarrier for rotation about the central axis of said roll-up cylinder,and pawl means for engaging said circular arrays of ratchet teeth andblocking rotation of said one-piece belt carrier in a safety beltunwinding direction, said pawl means including a pair of blockingsurface means at least partially disposed in said openings in said legsections and being movable along paths extending parallel to the innerand outer side surfaces of said leg sections between disengagedpositions spaced from said circular arrays of ratchet teeth and engagedpositions engaging said circular arrays of teeth to block rotation ofsaid one-piece belt carrier.